Furnace for steam-boilers.



Patented December 15, 1903.

. UNITED STATES PATENT OFFICE.

PHILIP J. GRAU, on TYRONE, PENNSYLVANIA.

FURNACE FOR STEAM-BOILERS.

SPIEGIFIGATION forming part of Letters Patent No. 746,957, datedDecember 15, 1903.

l v Application filed October 15, 1992;. Serial No. 127.819. (No model.)

To all whom it may concern: w 2

Be it known that I, PHILIP. J. GRAU, off Tyrone, county of Blair,Stateof Pennsylvania, have inventedan Improvement in Fur-i naces forSteam-Boilers, of which the follow-;

' triangular in. cross-section, so as to presenting is a specification.

My invention hasreference to furnaces for steam-boilers; and it consistsof certainim-j provements which are fully set forth in the{ followingspecification and shown in the ac-f companying drawings, which form apart 5 rear portion of each of the columns may be thereof.

v The object of my invention is to provide a. construction ofboiler-setting which shall supply the furnace with superheated air atthei bridge to consume the carbon-d net and smoke or unburned gasespassing fromthe furnace; under the boiler and at the same time cause 5the air in the act of being heated to cool the g side walls or lining ofthe furnace proper, as l way d of the bridge-cap D. The inclined pointedout hereinafter.

My invention consists in providing the side I walls of the furnace withfines through which air is forced to cool the said side walls and alsocause the air to be superheated, thesaid furnace being further providedwith a bridge formedof fines through which the air from p the side wallsis allowed to escape forthe purpose of burning the gases, carbon'parti-.1 any number) form between them throats L,

cles, and smoke passing from the furnace.

My invention also comprehends details of construction which, togetherwith the above features, will be better understood by refe-rdotted linesin Fig. 2.

once to the drawings, in which- Figure 1 is a sectional elevationthrough a I furnace, showing my improvements applied to steam-boilers,the said section being taken i on the line 2 z of Fig. 2. Fig. 2 is asectional plan view of same on line so a: of Fig. 1. Fig. 3 is avertical sectional plan view of same on line y y of Fig. 1. tion throughthe upper part of the bridgewall and column, taken on the line 10 w ofFig. 5; and Fig. 5 is a transverse section of r the said column on line8 s of Fig. 4.

A represents a steam-boiler and may be of i bridge-wall at the rear ofthe grate-bars. The" upper portion or cap of the bridge-wall I form offire-brick, preferably molded into a tubu- Fig. 4 is a vertical sec- Ilarbox D, with an inclined front wall having a longitudinal air-passaged and a series of apertures at the top for receiving the air-col .umns.

E shows a series of air-coin mns, preferably toward. the grate-bars twoinclined walls 2. The'lower part of these columns is provided withshanks T, adapted to fit into the upper part of the box-shapedfire-brick cap D of the bridge, as is clearly shown in Fig. 4. The

R, opening at the bottom into the passagefaces 6 of the columns areprovided with a series of apertures 4, opening from the passage-way R.The height of the columns is preferably such as to fit approximately tothe underside of. the boiler, as is shown clearly in Fig. 3, but wouldof course be shaped differently with difierent boilers. The series ofvertical columns E (of which there may be gradually lessening in widthas they approach from the front to the rear. The columns E may bestaggered, if desired, as indicated in The side Walls K of the furnaceare lined with inverted- L-shaped fire --brick, which when assembledformaseries of inclosed passage-ways k of sinuous form opening at thefront of the boiler-setting into the air-supply pipes H. and at the capD. l The supplypipes H are provided with valves 7:. of suitableconstruction and connect with a main flue H extending under the door tothe blower J. A valve 1' may be employed in this main flue H to controlthe flow of air through it.

Air may be admitted to the bridge-cap D through a hollow floor F, whichmay be provided with a series of hal de-plates or walls f, forming asinons passage-way G, communicating at one end of the cap D and at thefree end in a pipe H, provided with a suitable valve I and, if desired,communicating with a blower or fan J of any suitable construction. Theblower J may be omitted, if desired. In this manner the air, passingthrough the floor F becomes superheated and emerges from the apertures rof the columns E in a highly-superheated condition, it being firstheated in the floor F and then superheated to a greater extent inpassing through the bridge-wall and columns. When the air escapes fromthe columns, it is directed toward the passing products of combustionand is carried backward with said products of combustion and forced intointimate contact therewith while the said products are pass ing over thehighly-heated surface of the columns, thus insuring the most thoroughcommingling and superheating of theentire gases. As these combined gasespass through the throats L they are condensed into the most thoroughcontact or admixture and lead from the rear in strong heating-flames. Itwill now be seen that the air may be directed wholly through thehollow-floor superheater F on its'way to the bridge-cap flue d or whollythrough the main H and the side fines is of the furnace-walls K orwholly through each of the superheating devices, as desired. The air ineither case is thoroughly heated before emerging from the uprightcolumns E, and in case of the side flues it it may be regulated toinsure a proper quantity of air passing through each of the walls K.While these furnace side walls act as perfect superl heaters for theair, the air, on the otherhand,

keepsthem from overheating and burning.

out. This construction overcomes the destruction difficulty'which sofrequently occurs in furnaces of ordinary construction by insuringexceptionally long life to the lining; Aside from the saving in expensein labor and material there is also the great saving in loss of use ofthe boiler, which loss heretofore occurred whenever the side walls wererequired to be rebuilt. The side walls may be of any length foundconvenient and formed in any way desired so long as they cool the liningand act as flues for conveyance of air.

Where it is not desired to superheat the air before passing through thecolumns, it may be directly passed into the box-cap D by an air-fiue Hprovided with a suitable valve L which may be controlled by a chain 71,as clearly shown in Figs. 2 and 3. In some cases it is not desiredtoadmit air from the columns E at all, as the superheating effect of thesaid columns of refractory material insures all the requirements where aslower and more uniform temperature is necessary.

by Letters Patent, is

1. In a furnace for steam-boilers, the combination of the grate withside walls provided with sinuous air-passages formed by L-shapedfire-brick, a hollow bridge-wall having openings in its upper surface,and receiving heated air from the passages in the side walls, means forforcing air through the passages of the side walls, hollow columns ofrefractory material fitted into said openings and having inclined facesat, the front or forward end provided with air-orifices opening throughthem into the interior and which columns are so arranged as to form aseries of parallel vertical passages through which the products ofcombustion from the grate are required to pass.

2. In a furnace for steam-boilers, the combination of the grate, sidewalls on each side of the grate provided with air-passages, arranged insinuous form adapted to receive the air at the top and deliver it fromthe bottom in heated condition, a hollow bridge-wall having openingsinto the lower parts of the air-passages and also into the furnace-spaceabove the grate, a blower, pipes leading from the blower to the upperpart of the air-passages, and separate valves for controlling the supplyof air to each of the air-passages.

3. In a furnace for steam-boilers, the combination of the grate, twoindependent and parallel side walls on each side of the grate providedwith air-passages formed in sinuous form therein by the fire-bricklining, means for independently circulating air through the air-passagesof the two side walls from the top downward, and altransversepassage-way across the rear of the fire-box in which the lower part ofeach of the passage-ways open and provided with apertures through whichthe combined heated currents of air pass into the furnace.

4. In a furnacevfor steam-boilers, the com- PHILIP J. GRAU.

Witnesses:

SAMUEL GRAHAM, R. S. YINGER.

